T cell which expresses a gamma-delta t cell receptor (tcr) and a chimeric antigen receptor (car)

ABSTRACT

The present invention provides a T cell which expresses a gamma-delta T cell receptor (TCR) and a chimeric antigen receptor (CAR), wherein the CAR comprises: an antigen binding domain; a transmembrane domain; and a co-stimulatory intracellular signalling domain; wherein the intracellular signalling domain provides a co-stimulatory signal to the T cell following binding of antigen to the antigen binding domain.

FIELD OF THE INVENTION

The present invention relates to immunotherapeutic T cells. In particular, the invention provides immunotherapeutic gamma-delta T cells comprising a chimeric antigen receptor (CAR).

BACKGROUND TO THE INVENTION

Chimeric antigen receptors (CARs) developed for cancer immunotherapy combine an extracellular antigen recognition domain with signalling domains specific for effector cells within a single molecule. The most common CAR system involves an antigen recognition domain derived from a monoclonal antibody fused to signalling domains which provide activating signals for T cells.

Typically, the signalling domains of a CAR provides cytotoxicity, proliferation and survival signals to activate the effector cell upon binding of antigen to the antigen recognition domain (Signals 1 and 2).

A limitation of this technology is potential ‘on target-off tumour toxicity’. This toxicity is caused by the recognition of low levels of a cancer-associated antigen recognised by a CAR on normal tissues. For instance GD2 is a target for neuroblastoma but also is expressed on nerves; and PSMA is a target for prostate cancer cells but is also found on normal kidney, liver and colon cells, and brain astrocytes. This problem is more profound in solid tumours where there is a dearth of highly selective targets.

Thus there is a need for cancer immunotherapies which address the above problems.

SUMMARY OF ASPECTS OF THE INVENTION

The present inventors have determined a mechanism of reducing ‘on target-off tumour toxicity’ by using CARs in gamma delta (γδ) T-cells. In the system described herein, a CAR is used to provide a co-stimulatory signal (signal 2) to a γδ T-cell upon binding of antigen to the antigen recognition domain of the CAR. In this way, signal 2 is only provided to the T-cell upon binding of the CAR to its target antigen (FIG. 2A). Signal 1 for γδ T-cell activation is provided by the endogenous TCR, which is activated by danger signals, such as phosphoantigens.

A γδ T-cell requires both signal 1 and signal 2 for optimal effector function. Thus, in the present system the γδ T-cell will only be fully activated for cytotoxicity, proliferation and cytokine secretion if the target cell: (i) expresses the antigen recognised by the CAR; and (ii) expresses danger signals recognised by the endogenous γδ TCR.

Thus, in a first aspect the present invention provides a T cell which expresses a gamma-delta T cell receptor (TCR) and a chimeric antigen receptor (CAR), wherein the CAR comprises;

-   -   (i) an antigen binding domain;     -   (ii) a transmembrane domain; and     -   (iii) a co-stimulatory intracellular signalling domain;         wherein the intracellular signalling domain provides a         co-stimulatory signal to the T cell following binding of antigen         to the antigen binding domain.

As such, binding of a first antigen to the γδ TCR results in signal 1 production and binding of a second antigen to the antigen binding domain of the CAR results in signal 2 production.

The antigen binding domain may be capable of binding to a tumour-associated antigen (TAA).

The antigen binding domain may be capable of binding to GD2, CD33, CD19 or EGFR.

The intracellular signalling domain may comprise the DAP10, CD28, CD27, 41BB, OX40, CD30, IL2-R, IL7-R, IL21-R, NKp30, NKp44 or DNAM-1 (CD226) signalling domain.

The transmembrane domain of the CAR may comprise a CD8 stalk or a CD28 transmembrane domain.

The intracellular signalling domain of the CAR may comprise the DAP10 signalling domain.

The CAR may further comprise a spacer domain between the antigen binding domain and the transmembrane domain.

The γδ TCR may be capable of binding to a phosphoantigen/butyrophilin 3A1 complex; major histocompatibility complex class I chain-related A (MICA); major histocompatibility complex class I chain-related B (MICB); NKG2D ligand 1-6 (ULBP 1-6); CD1c; CD1d; endothelial protein C receptor (EPCR); lipohexapeptides; phycoreythrin or histidyl-tRNA-synthase.

The CAR may comprise one of the following amino acid sequences:

(aCD33-Fc-DAP10 CAR) SEQ ID NO: 1 MAVPTQVLGLLLLWLTDARCDIQMTQSPSSLSASVGDRVTITCRASEDIY FNLVWYQQKPGKAPKLLIYDTNRLADGVPSRFSGSGSGTQYTLTISSLQP EDFATYYCQHYKNYPLTFGQGTKLEIKRSGGGGSGGGGSGGGGSGGGGSR SEVQLVESGGGLVQPGGSLRLSCAASGFTLSNYGMHWIRQAPGKGLEWVS SISLNGGSTYYRDSVKGRFTISRDNAKSTLYLQMNSLRAEDTAVYYCAAQ DAYTGGYFDYWGQGTLVTVSSMDPAEPKSPDKTHTCPPCPAPPVAGPSVF LFPPKPKDTLMIARTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKP REEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKG QPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNY KTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSL SLSPGKKDPKFWVLVVVGGVLACYSLLVTVAFIIFWVCARPRRSPAQEDG KVYINMPGRG (aGD2-Fc-DAP10 CAR) SEQ ID NO: 2 METDTLLLWVLLLWVPGSTGQVQLQESGPGLVKPSQTLSITCTVSGFSLA SYNIHWVRQPPGKGLEWLGVIWAGGSTNYNSALMSRLTISKDNSKNQVFL KMSSLTAADTAVYYCAKRSDDYSWFAYWGQGTLVTVSSGGGGSGGGGSGG GGSENQMTQSPSSLSASVGDRVTMTCRASSSVSSSYLHWYQQKSGKAPKV WIYSTSNLASGVPSRFSGSGSGTDYTLTISSLQPEDFATYYCQQYSGYPI TFGQGTKVEIKRSDPAEPKSPDKTHTCPPCPAPPVAGPSVFLFPPKPKDT LMIARTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTY RVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYT LPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDS DGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGKKDP KFWVLVVVGGVLACYSLLVTVAFIIFWVCARPRRSPAQEDGKVYINMPGR G

In a further aspect the present invention provides a CAR comprising; (i) an antigen-binding domain; (ii) a transmembrane domain; and (iii) an intracellular signalling domain; wherein the intracellular signalling domain comprises a co-stimulatory intracellular signalling domain but does not comprise a CD3 endodomain.

The co-stimulatory intracellular signalling domain may be selected from a DAP10, CD28, CD27, 41BB, OX40, CD30, IL2-R, IL7-R, IL21-R, NKp30, NKp44 or DNAM-1 (CD226) signalling domain.

In a second aspect the present invention provides a CAR comprising, an antigen-binding domain; a transmembrane domain; and an intracellular signalling domain; wherein the intracellular signalling domain comprises a DAP10 signalling domain. The intracellular signalling domain may consist of or consist essentially of a DAP10 signalling domain.

In a particular embodiment the intracellular signalling domain of the CAR according to the second aspect of the invention does not comprise a CD3 endodomain.

The CAR according to the second aspect of the invention may be a CAR as defined in the first aspect of the invention.

In a third aspect the present invention provides a nucleic acid sequence encoding a CAR as defined in the first or second aspects of the invention.

In a fourth aspect the present invention provides a vector comprising a nucleic acid sequence as defined by the third aspect of the invention.

The vector may be a retroviral vector, a lentiviral vector or a transposon.

In a fifth aspect the present invention relates to method for making a cell according to the first aspect of the invention, which comprises the step of introducing: a nucleic acid sequence according to the third aspect of the invention or a vector according to fourth aspect of the invention into a cell.

The method may comprise the step of stimulating the cell with a gamma delta T cell stimulating agent.

The γδ T cell stimulating agent may be selected from, for example, isopentenyl pyrophosphate (IPP); analogs of IPP such as bromohydrin pyrophosphate and (E)-4-Hydroxy-3-methyl-but-2-enyl pyrophosphate; and inhibitors of farnesyl pyrophosphate synthase (FPPS) such as aminobisphosphonates (e.g. zoledronate or pamidronate).

The cell may be from a sample isolated from a subject.

In a sixth aspect the present invention provides a pharmaceutical composition comprising a cell according to the first aspect of the present invention.

In a seventh aspect the present invention relates to a method for treating a disease, which comprises the step of administering a pharmaceutical composition according to the sixth aspect of the invention to a subject.

The method may comprise the step of administering a γδ T cell stimulating agent to the subject.

The γδ T cell stimulating agent may be selected from, for example, isopentenyl pyrophosphate (IPP); analogs of IPP such as bromohydrin pyrophosphate and (E)-4-Hydroxy-3-methyl-but-2-enyl pyrophosphate; and inhibitors of farnesyl pyrophosphate synthase (FPPS) such as aminobisphosphonates (e.g. zoledronate or pamidronate).

The method may comprise the following steps:

-   -   (i) isolation of a cell-containing sample from a subject;     -   (ii) transduction or transfection of cells with: a nucleic acid         sample according to the third aspect of the present invention or         a vector according to the fourth aspect of the present         invention; and     -   (iii) administering the cells from (ii) to the subject.

In an eighth aspect the present invention relates to a pharmaceutical composition according to the sixth aspect of the present invention for use in treating a disease.

In a ninth aspect the present invention relates to the use of a cell according to the first aspect of the present invention in the manufacture of a medicament for treating and/or preventing a disease.

The disease described herein may be cancer, microbial infection or viral infection.

The present invention therefore provides a γδ T cell which is only fully activated by, and therefore capable of killing, a target cell which expresses a first antigen which is capable of binding to the endogenous γδ TCR (and thus stimulating productive signal 1) and a second antigen which is capable of binding to the CAR (and thus stimulating productive signal 2).

The γδ T cells of the invention are therefore useful for reducing unwanted ‘on target-off tumour’ effects. In particular, a normal cell which expresses low levels of a TAA will not activate the γδ T cell of the invention as it will not express a danger signal recognised by the endogenous γδ TCR and thus will not provide signal 1, which is required for full activation of the γδ T cell.

DESCRIPTION OF THE FIGURES

FIG. 1—Diagram of the signalling required for full activation of a γδ T cell which results in killing of the target cell. A) and B) Signalling via the γδ TCR or co-receptors alone does not result in full activation of the γδ T cell. C) A combination of γδ TCR and co-receptor signalling results in full activation of the γδ T cell

FIG. 2—Illustrative diagram of a γδ T cell of the present invention. A) Normal activation of a γδ T cell by a target cell. B) Blocking of signal 2 by soluble NKG2D ligands secreted by cancer cells prevents full activation of γδ T cells. C) Full activation of a γδ T cell of the present invention by a transformed cell. D) Normal healthy cells do not express danger signals recognised by endogenous γδ T cell receptors and do not fully activated γδ T cells of the present invention.

FIG. 3—Examples of illustrative CARs which may be used in the present invention

FIG. 4—Representative flow cytometric dot plots to illustrate co-expression of a γδ TCR (Vδ2) and GD2-DAP10 CAR (Fc, CD20 marker and CD34 marker) in a γδ T cell

FIG. 5—Killing of GD2+ cell lines LAN1 and TC71 by Vδ2 γδT cells transduced with the aGD2-Fc-DAP10 CAR

(A) Significant killing of GD2+ neuroblastoma cell line LAN1 is only seen when CAR transduced cells are used and not when non-transduced (NT) Vδ2 are used as effectors. (B) Additive effect of aGD2-Fc-DAP10 CAR when combined with 24h zoledronic acid exposure which increases phosphoantigen production, against the GD2+ Ewing sarcoma cell line TC71. (C) Addition of the CAR to αβT cells, which lack the signal 1 provided by the γδTCR in response to cellular stress, has no effect on cytotoxicity, unlike the effect of the CAR in Vδ2+ γδT cells. This indicates that the CAR signal alone is insufficient for T-cell activation. Error bars denote SEM for 3-6 independent donors.

FIG. 6—Killing of GD2+ cell line LAN1 and no killing of GD2− cell line SKNSH. Error bars denote SEM for 3-6 independent donors.

FIG. 7—Preservation of CAR expression following prolonged co-culture and GD2 specific expansion

(A) Co-culture was started 24 days after transduction (labelled DO). Serial analyses of cells for presence of CAR (Y axis) and TCRVδ2 (X axis) were taken in the presence of irradiated GD2+ (LAN1) and GD2− (SK-N-SH) neuroblastoma cells.

Representative data from 1 of 3 donors is shown. (B) Expansion of aGD2-Fc-DAP10 transduced Vδ2+ cells was only seen in the presence of irradiated GD2+ target cells (graphical representation, n=3 independent donors, error bars denote SEM).

FIG. 8—Flow cytometric staining for CD33 expression of AML cell lines (Nomo1, Sh1 and MV4; 11) and freshly isolated monocytes is equivalent.

FIG. 9—A) aCD33-DAP10-transduced Vδ2 cells spare monocytes in the absence of ZOL but aCD33-CD28z-transduced Vδ2 cells do not. B) aCD33-DAP10-transduced Vδ2 cells kill AML better than NT Vδ2 cells, but spare monocytes. Error bars indicate SEM for 3 independent donors.

FIG. 10—Nucleic acid and amino acid sequences of an anti-GD2-Fc-DAP10 CAR

FIG. 11—Nucleic acid and amino acid sequences of an anti-CD33-Fc-DAP10 CAR

FIG. 12—aCD33-DAP10-transduced Vδ2 cells spare haemopoietic stem cells but aCD33-CD28z-transduced Vδ2 cells do not. Normal human bone marrow was cultured overnight with the indicated CAR T cells. Surviving haemopoietic stem cells were assayed by myeloid colony formation in soft agar. Data is derived using transduced Vδ2 cells from three independent donors.

FIG. 13—Differential cross-linking of “costimulation-only” CAR and Vγ9vδ2 TCR leads to differential cytokine responses. Top; Schematic of experimental design. Biotinylated beads are coated with (A) no/irrelevant antibodies, or (B) antibodies to bind either the TCR (anti-CD3) or the CAR (anti-Ig binding the spacer region of the CAR); C) following cross linking, intracellular cytokine secretion is used to measure activation. As a control, stimulatory anti-CD3/CD28 beads (Miltenyi) are used. Bottom-left: representative FACS plots; bottom-right: cytokine responses to cross linking show that the “costimulation-only” CAR cross linking leads to a TNF-α response but that additional TCR engagement is required for full response comprising both interferon gamma and TNF-α. Data is means+/−SD of 5 donors.

DETAILED DESCRIPTION γδ T Cell

T-cells are divided into two groups based on their T-Cell Receptor (TCR) components. The TCR heterodimer consists of an α and β chain in 95% of T cells. These recognise foreign antigens via peptides presented by MHC molecules on antigen presenting cells and are essential for adaptive immunity.

5% of T cells have TCRs consisting of γ and δ chains. γδ TCRs are MHC independent and detect markers of cellular stress expressed by tumours.

γδ T cells recognize pathogens and transformed cells in an HLA-unrestricted manner. They respond to markers of cellular stress (e.g. phosphoantigens released by transformed cells as by-products of the mevalonate biosynthetic pathway). γδ T cells display both innate cytotoxic functions and antigen-presenting capability, particularly in the presence of antibody-opsonized target cells.

γδ T-cells are responsible for “lymphoid stress surveillance,” i.e., sensing and responding immediately to infections or non-microbial stress without the need of clonal expansion or de novo differentiation.

The activation of γδ T cells is regulated by a balance between stimulatory and inhibitory signals. They are activated by γδ TCR ligands (e.g. phosphoantigens) in combination with MHC-associated ligands of the activatory receptor killer cell lectin-like receptor subfamily K, member 1 (KLRK1), also known as NKG2D, such as MHC class I polypeptide-related sequence A (MICA), MICB, and various members of the UL16-binding protein (ULBP) family.

γδ cells also express killer-cell immunoglobulin-like receptors (KIRs), which can be either activatory or inhibitory, including killer cell immunoglobulin-like receptor, 2 domains, long cytoplasmic tail, 1 (KIR2DL1) and killer cell immunoglobulin-like receptor, 3 domains, long cytoplasmic tail, 1 (KIR3DL1).

Full activation of a γδ T cell which results in the effective killing of a target cell requires productive signal 1 and signal 2 generation (FIGS. 1 and 2A).

γδ T-cells derive signal 1 of T cell activation from danger signal antigens present on transformed or infected cells. These danger signal antigens are recognised through the γδ TCR. Signal 2 of T cell activation for γδ T-cells is also commonly derived by danger signal molecules (such as MICA) present on transformed or infected cells. Signal 2 may be transduced, for example, through the NKG2D receptor and DAP 10 (FIG. 2A).

As a means of avoiding immune detection, cancer cells frequently secrete soluble NKG2D ligands effectively blocking signal 2 in γδ T-cells, thus preventing their activation and facilitating tumour infiltration (FIG. 2B).

In a first aspect, the present invention provides a T cell which expresses a γδ TCR and a CAR, wherein the intracellular signalling domain of the CAR provides a co-stimulatory signal to the T cell.

Thus, the arrangement of the γδ TCR and the CAR is such that the γδ TCR provides signal 1 and the CAR provides signal 2 upon binding to each receptor, respectively.

As used herein, co-stimulatory signal is synonymous with signal 2, which is required for full γδ T cell activation.

Thus, a γδ T cell according to the first aspect of the present invention will only be fully activated and capable of killing a target cell which expresses a first antigen which is capable of binding to the γδ TCR (and thus stimulating productive signal 1) and a second antigen which is capable of binding to the CAR (and thus stimulating productive signal 2) (FIG. 2C).

In the absence of antigen binding to the γδ TCR, signal 1 is not generated and full γδ T cell activation is not achieved. In other words, in the absence of antigen binding to the γδ TCR, the γδ T cell is not stimulated to kill the target cell (FIG. 2D).

In the absence of antigen binding to the CAR, signal 2 is not generated and full γδ T cell activation is not achieved. In other words, in the absence of antigen binding to the CAR, the γδ T cell is not stimulated to kill the target cell.

The γδ T cell of the present invention may express any γδ TCR. Examples of γδ TCR ligands are known in the art (see Vantourout, P. & Hayday, A. Nat. Rev. Immunol. 13, 88-100 (2013), for example).

By way of example, the γδ TCR expressed by a cell of the present invention may recognise phosphoantigens (e.g. Isopentenyl pyrophosphate (IPP), Bromohydrin Pyrophosphate (BrHPP) and (E)-4-Hydroxy-3-methyl-but-2-enyl pyrophosphate (HMBPP)); major histocompatibility complex class I chain-related A (MICA); major histocompatibility complex class I chain-related B (MICB); NKG2D ligand 1-6 (ULBP 1-6); CD1c; CD1d; endothelial protein C receptor (EPCR); lipohexapeptides; phycoreythrin or histidyl-tRNA-synthase.

One advantage of the cell of the present invention is that it comprises a CAR comprising (i) an antigen binding domain which binds a specific antigen and (ii) a particular co-stimulatory endodomain. As such, the cell of the present invention will have a greater propensity towards activation in an environment comprising an antigen which can be bound by the CAR, as the binding of antigen by the CAR will result is signalling through the co-stimulatory endodomain and signal 2 production. For example, if the antigen-binding domain of the CAR is specific for a TAA, the cell of the present invention will have an increased propensity towards activation in a tumour environment where the TAA is expressed due to the co-stimulatory signal provided by the CAR.

Chimeric Antigen Receptor

The T cell according to the present invention expresses a chimeric antigen receptor (CAR).

Chimeric antigen receptors (CARs) are engineered receptors which graft an arbitrary specificity onto an immune effector cell. In a classical CAR, the specificity of a monoclonal antibody is grafted on to a T cell. CAR-encoding nucleic acids may be transferred to T cells using, for example, retroviral vectors. In this way, a large number of cancer-specific T cells can be generated for adoptive cell transfer. Phase I clinical studies of this approach show efficacy.

The target-antigen binding domain of a CAR is commonly fused via a spacer and transmembrane domain to a signaling endodomain. When the CAR binds the target-antigen, this results in the transmission of an activating signal to the T-cell it is expressed on.

Early CAR designs had endodomains derived from the intracellular parts of either the γ chain of the FcϵR1 or CD3ζ. Consequently, these first generation receptors transmitted immunological signal 1, which was sufficient to trigger T-cell killing of cognate target cells but failed to fully activate the T-cell to proliferate and survive. To overcome this limitation, compound endodomains have been constructed: fusion of the intracellular part of a T-cell co-stimulatory molecule to that of CD3ζ results in second generation receptors which can transmit an activating and co-stimulatory signal simultaneously after antigen recognition. The co-stimulatory domain most commonly used is that of CD28. This supplies the most potent co-stimulatory signal—namely immunological signal 2, which triggers T-cell proliferation. Some receptors have also been described which include TNF receptor family endodomains, such as the closely related OX40 and 41 BB which transmit survival signals. Even more potent third generation CARs have now been described which have endodomains capable of transmitting activation, proliferation and survival signals.

The γδ T cell of the present invention comprises a CAR which comprises a co-stimulatory signalling endodomain which transmits signal 2 to the γδ T cell upon the binding of target antigen.

The CARs of the T cell of the present invention may comprise a signal peptide so that when the CAR is expressed inside a cell, such as a T-cell, the nascent protein is directed to the endoplasmic reticulum and subsequently to the cell surface, where it is expressed.

The core of the signal peptide may contain a long stretch of hydrophobic amino acids that has a tendency to form a single alpha-helix. The signal peptide may begin with a short positively charged stretch of amino acids, which helps to enforce proper topology of the polypeptide during translocation. At the end of the signal peptide there is typically a stretch of amino acids that is recognized and cleaved by signal peptidase. Signal peptidase may cleave either during or after completion of translocation to generate a free signal peptide and a mature protein. The free signal peptides are then digested by specific proteases.

The signal peptide may be at the amino terminus of the molecule.

The signal peptide may comprise the SEQ ID NO: 6, 7 or 8 or a variant thereof having 5, 4, 3, 2 or 1 amino acid mutations (insertions, substitutions or additions) provided that the signal peptide still functions to cause cell surface expression of the CAR.

SEQ ID NO: 6: MGTSLLCVVMALCLLGADHADG

The signal peptide of SEQ ID NO: 6 is compact and highly efficient. It is predicted to give about 95% cleavage after the terminal glycine, giving efficient removal by signal peptidase.

SEQ ID NO: 7: MSLPVTALLLPLALLLHAARP

The signal peptide of SEQ ID NO: 7 is derived from IgG1.

SEQ ID NO: 8: MAVPTQVLGLLLLWLTDARC

The signal peptide of SEQ ID NO: 8 is derived from CD8.

Co-Stimulatory Intracellular Signalling Domain

The intracellular domain/endodomain is the signal-transmission portion of a classical CAR.

The γδ T cell of the present invention comprises a CAR which comprises a co-stimulatory signalling endodomain which transmits signal 2 to the γδ T cell upon the binding of target antigen. Accordingly, γδ T cell of the present invention comprises a CAR which does not transmit signal 1 to the γδ T cell upon the binding of target antigen.

T-cell costimulatory receptors are known to induce qualitative and quantitative changes that lower activation thresholds and prevent T cell energy and enhance T cell function.

A number of co-receptors for γδ T cells are known in the art. Productive signalling via one or more of these receptors can result in full activation of the γδ T cell and target cell killing.

The γδ T cell of the present invention comprises an intracellular signalling domain from a γδ T cell co-receptor, such that binding of antigen to the antigen-binding domain of the CAR generates productive signal 2 signalling in the γδ T cell.

The intracellular signalling domain may, for example, comprise the DAP10, CD28, CD27, 41BB, OX40, CD30, IL2-R, IL7-R, IL21-R, NKp30, NKp44 or DNAM-1 (CD226) signalling domain.

The intracellular signalling domain may comprise the DAP10 signalling domain.

DAP10 is a signalling subunit which associates with the NKG2D receptor (see FIG. 1). It is the exclusive binding partner and signalling intermediate for NKG2D and contains a YxxM activation motif that triggers the lipid kinase cascade.

An example of an amino acid sequence for a DAP10 signalling domain is shown below:

SEQ ID NO: 3 CARPRRSPAQEDGKVYINMPGRG

Further illustrative co-stimulatory domains are shown as SEQ ID NO: 9-19

(CD28 endodomain) SEQ ID NO: 9 KRSRLLHSDYMNMTPRRPGPTRKHYQPYAPPRDFAAY (CD27 endodomain) SEQ ID NO: 10 QRRKYRSNKGESPVEPAEPCHYSCPREEEGSTIPIQEDYRKPEPACSP (41BB endodomain) SEQ ID NO: 11 KRGRKKLLYIFKQPFMRPVQTTQEEDGCSCRFPEEEEGGCEL (OX40 endodomain) SEQ ID NO: 12 RRDQRLPPDAHKPPGGGSFRTPIQEEQADAHSTLAKI (CD30 endodomain) SEQ ID NO: 13 HRRACRKRIRQKLHLCYPVQTSQPKLELVDSRPRRSSTQLRSGASVTEPV AEERGLMSQPLMETCHSVGAAYLESLPLQDASPAGGPSSPRDLPEPRVST EHTNNKIEKIYIMKADTVIVGTVKAELPEGRGLAGPAEPELEEELEADHT PHYPEQETEPPLGSCSDVMLSVEEEGKEDPLPTAASGK (IL2-R endodomain) SEQ ID NO: 14 TWQRRQRKSRRTI (IL7-R endodomain) SEQ ID NO: 15 KKRIKPIVWPSLPDHKKTLEHLCKKPRKNLNVSFNPESFLDCQIHRVDDI QARDEVEGFLQDTFPQQLEESEKQRLGGDVQSPNCPSEDVVITPESFGRD SSLTCLAGNVSACDAPILSSSRSLDCRESGKNGPHVYQDLLLSLGTTNST LPPPFSLQSGILTLNPVAQGQPILTSLGSNQEEAYVTMSSFYQNQ (IL21-R endodomain) SEQ ID NO: 16 SLKTHPLWRLWKKIWAVPSPERFFMPLYKGCSGDFKKWVGAPFTGSSLEL GPWSPEVPSTLEVYSCHPPRSPAKRLQLTELQEPAELVESDGVPKPSFWP TAQNSGGSAYSEERDRPYGLVSIDTVTVLDAEGPCTWPCSCEDDGYPALD LDAGLEPSPGLEDPLLDAGTTVLSCGCVSAGSPGLGGPLGSLLDRLKPPL ADGEDWAGGLPWGGRSPGGVSESEAGSPLAGLDMDTFDSGFVGSDCSSPV ECDFTSPGDEGPPRSYLRQWVVIPPPLSSPGPQAS (NKp30 endodomain) SEQ ID NO: 17 GSTVYYQGKCLTWKGPRRQLPAVVPAPLPPPCGSSAHLLPPVPGG (NKp44 endodomain) SEQ ID NO: 18 WWGDIWWKTMMELRSLDTQKATCHLQQVTDLPWTSVSSPVEREILYHTVA RTKISDDDDEHTL (DNAM-1 (CD226) endodomain) SEQ ID NO: 19 NRRRRRERRDLFTESWDTQKAPNNYRSPISTSQPTNQSMDDTREDIYVNY PTFSRRPKTRV

The intracellular signalling domain may comprise, consist essentially of or consist of a co-stimulatory signalling domain as described herein.

The intracellular signalling domain may comprise a sequence shown as SEQ ID NO: 3 or 9-19 or a variant thereof.

The variant may comprise a sequence which shares at least 75% sequence identity with SEQ ID NO: 3 or 9-19 provided that the sequence provides an effective co-stimulatory signaling domain.

The variant may comprise a sequence which shares at least 80% sequence identity with SEQ ID NO: 3 or 9-19 provided that the sequence provides an effective co-stimulatory signaling domain.

The variant may comprise a sequence which shares at least 85% sequence identity with SEQ ID NO: 3 or 9-19 provided that the sequence provides an effective co-stimulatory signaling domain.

The variant may comprise a sequence which shares at least 90% sequence identity with SEQ ID NO: 3 or 9-19 provided that the sequence provides an effective co-stimulatory signaling domain.

The variant may comprise a sequence which shares at least 95% sequence identity with SEQ ID NO: 3 or 9-19 provided that the sequence provides an effective co-stimulatory signaling domain.

The variant may comprise a sequence which shares at least 99% sequence identity with SEQ ID NO: 3 or 9-19 provided that the sequence provides an effective co-stimulatory signaling domain.

In one embodiment, the intracellular signalling domain may comprise a sequence shown as SEQ ID NO: 3 or a variant thereof which shares at least 75, 80, 85, 90, 95 or 99% sequence identity with SEQ ID NO: 3, provided that the sequence provides an effective co-stimulatory signaling domain.

In one embodiment, the endodomain does not comprise the CD3 endodomain. For example, the endodomain does not comprise the CD3 epsilon chain, the CD3 gamma chain and/or the CD3 delta chain. In a particular embodiment, the endodomain does not comprise the CD3-zeta endodomain.

An illustrative CD3-zeta endodomain is shown as SEQ ID NO: 26.

(CD3 zeta endodomain) SEQ ID NO: 26 RSRVKFSRSADAPAYQQGQNQLYNELNLGRREEYDVLDKRRGRDPEMGG KPRRKNPQEGLYNELQKDKMAEAYSEIGMKGERRRGKGHDGLYQGLSTA TKDTYDALHMQALPPR

The CD3-zeta endodomain as described herein may comprise or consist of SEQ ID NO: 26 or a variant thereof which has at least 80%, 85%, 90%, 95%, 98% or 99% sequence identity to SEQ ID NO: 26 and provides an effective transmembrane domain/intracellular T cell signaling domain.

Antigen Binding Domain

The antigen binding domain is the portion of the CAR which recognizes antigen. Numerous antigen-binding domains are known in the art, including those based on the antigen binding site of an antibody, antibody mimetics, and T-cell receptors. For example, the antigen-binding domain may comprise: a single-chain variable fragment (scFv) derived from a monoclonal antibody; a natural ligand of the target antigen; a peptide with sufficient affinity for the target; a single domain antibody; an artificial single binder such as a Darpin (designed ankyrin repeat protein); or a single-chain derived from a T-cell receptor.

The antigen binding domain may comprise a domain which is not based on the antigen binding site of an antibody. For example the antigen binding domain may comprise a domain based on a protein/peptide which is a soluble ligand for a tumour cell surface receptor (e.g. a soluble peptide such as a cytokine or a chemokine); or an extracellular domain of a membrane anchored ligand or a receptor for which the binding pair counterpart is expressed on the tumour cell.

By way of example, the examples described herein relate to CARs which bind GD2 and CD33, respectively.

The antigen binding domain may be based on a natural ligand of the antigen.

The antigen binding domain may comprise an affinity peptide from a combinatorial library or a de novo designed affinity protein/peptide.

Tumour-Associated Antigen (TAA)

The antigen binding domain may bind to a tumour-associated antigen (TAA).

An extensive range of TAAs are known in the art and the CAR used in the present invention may comprise any antigen binding domain which is capable of specifically binding to any TAA.

By way of example, the CAR for use in the present invention may be capable of specifically binding to a TAA listed in Table 1.

TABLE 1 Antigen Tumour of interest CD20 B-cell lymphomas, CLL CD19 Pre-B ALL, B-cell lymphoma, CLL CD22 Pre-B ALL, B-cell lymphomas, CLL CD30 Hodgkin's lymphoma, ALCL CD52 T-cell AML, Pre-B ALL CD70 Hodgkins Lymphoma, DLCL, Renal cell carcinoma, EBV+ glioblastoma, undifferentiated nasopharyngeal sarcoma CD33 AML, MDS, APL, CML, JMML, ALL (18% only) CD47 Pre-B ALL, T cell ALL, AML IL7 receptor α Pre-B ALL, B cell lymphomas TSLPR Pre-B ALL (7%), Pre-B aLL in Down's syndrome (60%) ROR1 Pre-B ALL, CLL mantle cell lymphoma GD2 Neuroblastoma, osteosarcoma, Ewing sarcoma, soft tissue sarcomas, melanoma IL13Rα2 Glioblastoma, DIPG, melanoma, various carcinomas, mesothelioma VEGFR2 Tumour vasculature HER2 Osteosarcoma, colon cancer, breast cancer ALK Neuroblastoma, neuroectodermal tumours, glioblastoma, rhabdomyosarcoma, melanoma EGFRvIII Glioma FGFR4 Rhabdomyosarcoma B7-H3 Neuroblastoma Glypican- Wilm's tumour, neuroblastoma, rhabdomyosarcoma, 3/Glypican-5 hepatic carcinaoma, melanoma FOLR1 Rhabdomyosarcoma, osteosarcoma

A problem associated with the targeting of TAAs in cancer immunotherapy is that low levels of the TAAs may be expressed on normal tissues. For instance GD2 is a neuroblastoma TAA, but it is also expressed on nerves; PSMA is a prostate cancer TAA but also is found on normal kidney, liver and colon cells, and brain astrocytes. This problem is more profound in solid tumours where there is a dearth of highly selective targets.

The expression of TAAs on normal, healthy cells may result in ‘on-target, off-tumour’ side effects. The present invention mitigates these effects because the γδ T cell of the present invention is only activated by cells which express a ligand for both the γδ TCR and the CAR. Normal, healthy cells which express the TAA at low levels will therefore not activate the γδ T cell of the present invention because they do not express a danger signal antigen capable of binding to the γδ TCR (FIG. 2D).

The antigen binding domain of the CAR may be capable of binding GD2, CD33, CD19 or EGFR.

Disialoganglioside (GD2, for example as shown by pubchem: 6450346) is a sialic acid-containing glycosphingolipid expressed primarily on the cell surface. The function of this carbohydrate antigen is not completely understood; however, it is thought to play an important role in the attachment of tumour cells to extracellular matrix proteins. GD2 is densely, homogenously and almost universally expressed on neuroblastoma. In normal tissues, GD2 expression is largely limited to skin melanocytes, and peripheral pain fibre myelin sheaths. Within the CNS, GD2 appears to be an embryonic antigen but is found dimly expressed in scattered oligodendrocytes and within the posterior pituitary.

The antigen binding domain may comprise a sequence shown as SEQ ID NO: 20 or a variant thereof, providing that the variant retains the ability to bind to GD2.

SEQ ID NO: 20 METDTLLLWVLLLWVPGSTGQVQLQESGPGLVKPSQTLSITCTVSGFSLA SYNIHWVRQPPGKGLEWLGVIWAGGSTNYNSALMSRLTISKDNSKNQVFL KMSSLTAADTAVYYCAKRSDDYSWFAYWGQGTLVTVSSGGGGSGGGGSGG GGSENQMTQSPSSLSASVGDRVTMTCRASSSVSSSYLHWYQQKSGKAPKV WIYSTSNLASGVPSRFSGSGSGTDYTLTISSLQPEDFATYYCQQYSGYPI TFGQGTKVEIKRS

The antigen binding domain may comprise a sequence shown as SEQ ID NO: 20 or a variant thereof which shares at least 75, 80, 85, 90, 95 or 99% sequence identity with SEQ ID NO: 20, providing that the variant retains the ability to bind to GD2.

CD33 (for example as shown by Uniprot accession number P20138) is a putative adhesion molecule of myelomonocytic-derived cells that mediates sialic-acid dependent binding to cells. It is usually considered myeloid-specific, but it can also be found on some lymphoid cells.

The antigen binding domain may comprise a sequence shown as SEQ ID NO: 21 or a variant thereof, providing that the variant retains the ability to bind to GD2.

SEQ ID NO: 21 MAVPTQVLGLLLLWLTDARCDIQMTQSPSSLSASVGDRVTITCRASEDIY FNLVWYQQKPGKAPKLLIYDTNRLADGVPSRFSGSGSGTQYTLTISSLQP EDFATYYCQHYKNYPLTFGQGTKLEIKRSGGGGSGGGGSGGGGSGGGGSR SEVQLVESGGGLVQPGGSLRLSCAASGFTLSNYGMHWIRQAPGKGLEWVS SISLNGGSTYYRDSVKGRFTISRDNAKSTLYLQMNSLRAEDTAVYYCAAQ DAYTGGYFDYWGQGTLVTVSSM

The antigen binding domain may comprise a sequence shown as SEQ ID NO: 21 or a variant thereof which shares at least 75, 80, 85, 90, 95 or 99% sequence identity with SEQ ID NO: 21, providing that the variant retains the ability to bind to GD2.

The human CD19 antigen is a 95 kd transmembrane glycoprotein belonging to the immunoglobulin superfamily (for example as shown by Uniprot P15391). CD19 is expressed very early in B-cell differentiation and is only lost at terminal B-cell differentiation into plasma cells. Consequently, CD19 is expressed on all B-cell malignancies apart from multiple myeloma. CD19 is also expressed by the normal B cell compartment.

EGFR (for example as shown by Uniprot accession number P00533) is a receptor tyrosine kinase which binds ligands of the EGF family and activates several signaling cascades to convert extracellular cues into appropriate cellular responses. Known ligands include EGF, TGFA/TGF-alpha, amphiregulin, epigen/EPGN, BTC/betacellulin, epiregulin/EREG and HBEGF/heparin-binding EGF. EGFR is expressed at high levels by many cancer cells. However, it is also expressed by normal, healthy cells.

Spacer Domain

CARs may comprise a spacer sequence to connect the antigen-binding domain with the transmembrane domain and spatially separate the antigen-binding domain from the endodomain. A flexible spacer allows the antigen-binding domain to orient in different directions to facilitate binding.

The spacer sequence may, for example, comprise an IgG1 Fc region, an IgG1 hinge or a human CD8 stalk or the mouse CD8 stalk. The spacer may alternatively comprise an alternative linker sequence which has similar length and/or domain spacing properties as an IgG1 Fc region, an IgG1 hinge or a CD8 stalk. A human IgG1 spacer may be altered to remove Fc binding motifs.

Examples of amino acid sequences for these spacers are given below:

(hinge-CH₂CH₃ of human IgG1) SEQ ID NO: 22 AEPKSPDKTHTCPPCPAPPVAGPSVFLFPPKPKDTLMIARTPEVTCVVVD VSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLN GKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSL TCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKS RWQQGNVFSCSVMHEALHNHYTQKSLSLSPGKKD (human CD8 stalk) SEQ ID NO: 23 TTTPAPRPPTPAPTIASQPLSLRPEACRPAAGGAVHTRGLDFACDI (human IgG1 hinge) SEQ ID NO: 24 AEPKSPDKTHTCPPCPKDPK

The spacer may be a variant of any of SEQ ID NO: 22 to 24 which shares at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95% or at least 99% sequence identity with SEQ ID NO: 22 to 24 and retains the functional activity of the amino acid sequence shown as SEQ ID NO: 9 to 11.

Transmembrane Domain

The transmembrane domain is the sequence of the CAR that spans the membrane.

A transmembrane domain may be any protein structure which is thermodynamically stable in a membrane. This is typically an alpha helix comprising of several hydrophobic residues. The transmembrane domain of any transmembrane protein can be used to supply the transmembrane portion of the invention. The presence and span of a transmembrane domain of a protein can be determined by those skilled in the art using the TMHMM algorithm (http://www.cbs.dtu.dk/services/TMHMM-2.0/). Further, given that the transmembrane domain of a protein is a relatively simple structure, i.e a polypeptide sequence predicted to form a hydrophobic alpha helix of sufficient length to span the membrane, an artificially designed TM domain may also be used (U.S. Pat. No. 7,052,906 B1 describes synthetic transmembrane components).

The transmembrane domain may be derived from any type I transmembrane protein. The transmembrane domain may be a synthetic sequence predicted to form a hydrophobic helix.

The transmembrane domain may be derived from CD28, which gives good receptor stability.

The transmembrane domain may comprise the sequence shown as SEQ ID NO: 25.

(CD28 transmembrane domain) SEQ ID NO: 25 FWVLVVVGGVLACYSLLVTVAFIIFWV

Nucleic Acid

The present invention further provides a nucleic acid sequence which encodes a CAR as described herein.

The nucleic acid sequence may be capable of encoding a CAR having the amino acid sequence shown as SEQ ID NO: 1 or SEQ ID NO: 2.

(aCD33-Fc-DAP10 CAR) SEQ ID NO: 4 ATGGCCGTGCCCACTCAGGTCCTGGGGTTGTTGCTACTGTGGCTTACAGA TGCCAGATGTGACATCCAGATGACACAGTCTCCATCTTCCCTGTCTGCAT CTGTCGGAGATCGCGTCACCATCACCTGTCGAGCAAGTGAGGACATTTAT TTTAATTTAGTGTGGTATCAGCAGAAACCAGGAAAGGCCCCTAAGCTCCT GATCTATGATACAAATCGCTTGGCAGATGGGGTCCCATCACGGTTCAGTG GCTCTGGATCTGGCACACAGTATACTCTAACCATAAGTAGCCTGCAACCC GAAGATTTCGCAACCTATTATTGTCAACACTATAAGAATTATCCGCTCAC GTTCGGTCAGGGGACCAAGCTGGAAATCAAAAGATCTGGTGGCGGAGGGT CAGGAGGCGGAGGCAGCGGAGGCGGTGGCTCGGGAGGCGGAGGCTCGAGA TCTGAGGTGCAGTTGGTGGAGTCTGGGGGCGGCTTGGTGCAGCCTGGAGG GTCCCTGAGGCTCTCCTGTGCAGCCTCAGGATTCACTCTCAGTAATTATG GCATGCACTGGATCAGGCAGGCTCCAGGGAAGGGTCTGGAGTGGGTCTCG TCTATTAGTCTTAATGGTGGTAGCACTTACTATCGAGACTCCGTGAAGGG CCGATTCACTATCTCCAGGGACAATGCAAAAAGCACCCTCTACCTTCAAA TGAATAGTCTGAGGGCCGAGGACACGGCCGTCTATTACTGTGCAGCACAG GACGCTTATACGGGAGGTTACTTTGATTACTGGGGCCAAGGAACGCTGGT CACAGTCTCGTCTATGGATCCCGCCGAGCCCAAATCTCCTGACAAAACTC ACACATGCCCACCGTGCCCAGCACCTCCCGTGGCCGGCCCGTCAGTCTTC CTCTTCCCCCCAAAACCCAAGGACACCCTCATGATCGCCCGGACCCCTGA GGTCACATGCGTGGTGGTGGACGTGAGCCACGAAGACCCTGAGGTCAAGT TCAACTGGTACGTGGACGGCGTGGAGGTGCATAATGCCAAGACAAAGCCG CGGGAGGAGCAGTACAACAGCACGTACCGTGTGGTCAGCGTCCTCACCGT CCTGCACCAGGACTGGCTGAATGGCAAGGAGTACAAGTGCAAGGTCTCCA ACAAAGCCCTCCCAGCCCCCATCGAGAAAACCATCTCCAAAGCCAAAGGG CAGCCCCGAGAACCACAGGTGTACACCCTGCCCCCATCCCGGGATGAGCT GACCAAGAACCAGGTCAGCCTGACCTGCCTGGTCAAAGGCTTCTATCCCA GCGACATCGCCGTGGAGTGGGAGAGCAATGGGCAACCGGAGAACAACTAC AAGACCACGCCTCCCGTGCTGGACTCCGACGGCTCCTTCTTCCTCTACAG CAAGCTCACCGTGGACAAGAGCAGGTGGCAGCAGGGGAACGTCTTCTCAT GCTCCGTGATGCATGAGGCCCTGCACAATCACTATACCCAGAAATCTCTG AGTCTGAGCCCAGGCAAGAAGGACCCCAAGTTCTGGGTCCTGGTGGTGGT GGGAGGCGTGCTGGCCTGTTACTCTCTCCTGGTGACCGTGGCCTTCATCA TCTTCTGGGTGTGCGCCAGACCACGGCGGAGCCCAGCCCAGGAGGACGGC AAGGTGTACATCAACATGCCCGGCCGCGGCTGA (aGD2-Fc-DAP10 CAR) SEQ ID NO: 5 ATGGAGACCGACACCCTGCTGCTGTGGGTGCTGCTGCTGTGGGTGCCAGG CAGCACCGGCCAGGTGCAGCTGCAGGAGTCTGGCCCAGGCCTGGTGAAGC CCAGCCAGACCCTGAGCATCACCTGCACCGTGAGCGGCTTCAGCCTGGCC AGCTACAACATCCACTGGGTGCGGCAGCCCCCAGGCAAGGGCCTGGAGTG GCTGGGCGTGATCTGGGCTGGCGGCAGCACCAACTACAACAGCGCCCTGA TGAGCCGGCTGACCATCAGCAAGGACAACAGCAAGAACCAGGTGTTCCTG AAGATGAGCAGCCTGACAGCCGCCGACACCGCCGTGTACTACTGCGCCAA GCGGAGCGACGACTACAGCTGGTTCGCCTACTGGGGCCAGGGCACCCTGG TGACCGTGAGCTCTGGCGGAGGCGGCTCTGGCGGAGGCGGCTCTGGCGGA GGCGGCAGCGAGAACCAGATGACCCAGAGCCCCAGCAGCTTGAGCGCCAG CGTGGGCGACCGGGTGACCATGACCTGCAGAGCCAGCAGCAGCGTGAGCA GCAGCTACCTGCACTGGTACCAGCAGAAGAGCGGCAAGGCCCCAAAGGTG TGGATCTACAGCACCAGCAACCTGGCCAGCGGCGTGCCCAGCCGGTTCAG CGGCAGCGGCAGCGGCACCGACTACACCCTGACCATCAGCAGCCTGCAGC CCGAGGACTTCGCCACCTACTACTGCCAGCAGTACAGCGGCTACCCCATC ACCTTCGGCCAGGGCACCAAGGTGGAGATCAAGCGGTCGGATCCCGCCGA GCCCAAATCTCCTGACAAAACTCACACATGCCCACCGTGCCCAGCACCTC CCGTGGCCGGCCCGTCAGTCTTCCTCTTCCCCCCAAAACCCAAGGACACC CTCATGATCGCCCGGACCCCTGAGGTCACATGCGTGGTGGTGGACGTGAG CCACGAAGACCCTGAGGTCAAGTTCAACTGGTACGTGGACGGCGTGGAGG TGCATAATGCCAAGACAAAGCCGCGGGAGGAGCAGTACAACAGCACGTAC CGTGTGGTCAGCGTCCTCACCGTCCTGCACCAGGACTGGCTGAATGGCAA GGAGTACAAGTGCAAGGTCTCCAACAAAGCCCTCCCAGCCCCCATCGAGA AAACCATCTCCAAAGCCAAAGGGCAGCCCCGAGAACCACAGGTGTACACC CTGCCCCCATCCCGGGATGAGCTGACCAAGAACCAGGTCAGCCTGACCTG CCTGGTCAAAGGCTTCTATCCCAGCGACATCGCCGTGGAGTGGGAGAGCA ATGGGCAACCGGAGAACAACTACAAGACCACGCCTCCCGTGCTGGACTCC GACGGCTCCTTCTTCCTCTACAGCAAGCTCACCGTGGACAAGAGCAGGTG GCAGCAGGGGAACGTCTTCTCATGCTCCGTGATGCATGAGGCCCTGCACA ATCACTATACCCAGAAATCTCTGAGTCTGAGCCCAGGCAAGAAGGACCCC AAGTTCTGGGTCCTGGTGGTGGTGGGAGGCGTGCTGGCCTGTTACTCTCT CCTGGTGACCGTGGCCTTCATCATCTTCTGGGTGTGCGCCAGACCACGGC GGAGCCCAGCCCAGGAGGACGGCAAGGTGTACATCAACATGCCCGGCCGC GGCTGA

The nucleic acid sequence may encode the same amino acid sequence as that encoded by SEQ ID NO: 1 or 2, but may have a different nucleic acid sequence, due to the degeneracy of the genetic code. The nucleic acid sequence may have at least 80, 85, 90, 95, 98 or 99% identity to the sequence shown as SEQ ID NO: 4 or SEQ ID NO: 5, provided that it encodes a CAR as defined in the first aspect of the invention.

Variant

Sequence comparisons can be conducted by eye, or more usually, with the aid of readily available sequence comparison programs. These publicly and commercially available computer programs can calculate sequence identity between two or more sequences.

Sequence identity may be calculated over contiguous sequences, i.e. one sequence is aligned with the other sequence and each amino acid in one sequence directly compared with the corresponding amino acid in the other sequence, one residue at a time. This is called an “ungapped” alignment. Typically, such ungapped alignments are performed only over a relatively short number of residues (for example less than 50 contiguous amino acids).

Although this is a very simple and consistent method, it fails to take into consideration that, for example, in an otherwise identical pair of sequences, one insertion or deletion will cause the following amino acid residues to be put out of alignment, thus potentially resulting in a large reduction in % homology when a global alignment is performed. Consequently, most sequence comparison methods are designed to produce optimal alignments that take into consideration possible insertions and deletions without penalising unduly the overall homology score. This is achieved by inserting “gaps” in the sequence alignment to try to maximise local homology.

However, these more complex methods assign “gap penalties” to each gap that occurs in the alignment so that, for the same number of identical amino acids, a sequence alignment with as few gaps as possible—reflecting higher relatedness between the two compared sequences—will achieve a higher score than one with many gaps. “Affine gap costs” are typically used that charge a relatively high cost for the existence of a gap and a smaller penalty for each subsequent residue in the gap.

This is the most commonly used gap scoring system. High gap penalties will of course produce optimised alignments with fewer gaps. Most alignment programs allow the gap penalties to be modified. However, it is preferred to use the default values when using such software for sequence comparisons. For example when using the GCG Wisconsin Bestfit package (see below) the default gap penalty for amino acid sequences is −12 for a gap and −4 for each extension.

Calculation of maximum % sequence identity therefore firstly requires the production of an optimal alignment, taking into consideration gap penalties. A suitable computer program for carrying out such an alignment is the GCG Wisconsin Bestfit package (University of Wisconsin, U.S.A; Devereux et al., 1984, Nucleic Acids Research 12:387). Examples of other software than can perform sequence comparisons include, but are not limited to, the BLAST package (see Ausubel et al., 1999 ibid—Chapter 18), FASTA (Atschul et al., 1990, J. Mol. Biol., 403-410) and the GENEWORKS suite of comparison tools. Both BLAST and FASTA are available for offline and online searching (see Ausubel et al., 1999 ibid, pages 7-58 to 7-60). However it is preferred to use the GCG Bestfit program.

Although the final sequence identity can be measured in terms of identity, the alignment process itself is typically not based on an all-or-nothing pair comparison. Instead, a scaled similarity score matrix is generally used that assigns scores to each pairwise comparison based on chemical similarity or evolutionary distance. An example of such a matrix commonly used is the BLOSUM62 matrix—the default matrix for the BLAST suite of programs. GCG Wisconsin programs generally use either the public default values or a custom symbol comparison table if supplied (see user manual for further details). It is preferred to use the public default values for the GCG package, or in the case of other software, the default matrix, such as BLOSUM62.

Once the software has produced an optimal alignment, it is possible to calculate % sequence identity. The software typically does this as part of the sequence comparison and generates a numerical result.

The terms “variant” according to the present invention includes any substitution of, variation of, modification of, replacement of, deletion of or addition of one (or more) amino acids from or to the sequence providing the resultant amino acid sequence retains substantially the same activity as the unmodified sequence.

Conservative substitutions may be made, for example according to the Table below. Amino acids in the same block in the second column and preferably in the same line in the third column may be substituted for each other:

ALIPHATIC Non-polar G A P I L V Polar - uncharged C S T M N Q Polar - charged D E K R AROMATIC H F W Y

It will be understood by a skilled person that numerous different polynucleotides and nucleic acids can encode the same polypeptide as a result of the degeneracy of the genetic code. In addition, it is to be understood that skilled persons may, using routine techniques, make nucleotide substitutions that do not affect the polypeptide sequence encoded by the polynucleotides described here to reflect the codon usage of any particular host organism in which the polypeptides are to be expressed.

A nucleic acid sequence or amino acid sequence as described herein may comprise, consist of or consist essentially of a nucleic acid sequence or amino acid sequence as shown herein.

Vector

The present invention also provides a vector which comprises a nucleic acid sequence according to the present invention. Such a vector may be used to introduce the nucleic acid sequence into a host cell so that it expresses and produces a molecule according to the first aspect of the invention.

The vector may, for example, be a plasmid or a viral vector, such as a retroviral vector or a lentiviral vector.

The vector may be capable of transfecting or transducing a T cell.

The vector may also comprise a nucleic acid sequence encoding a suicide gene, such as iCasp9 or RQR8.

A suicide-gene is a genetically encoded mechanism which allows selective destruction of adoptively transferred cells, such as T-cells, in the face of unacceptable toxicity.

Activation of Caspase 9 results in cell apoptosis. The activation mechanism behind Caspase 9 was exploited by the iCasp9 molecule. All that is needed for Caspase 9 to become activated, is overcoming the energic barrier for Caspase 9 to homodimerize. The homodimer undergoes a conformational change and the proteolytic domain of one of a pair of dimers becomes active. Physiologically, this occurs by binding of the CARD domain of Caspase 9 to APAF-1. In iCasp9, the APAF-1 domain is replaced with a modified FKBP12 which has been mutated to selectively bind a chemical inducer of dimerization (CID). Presence of the CID results in homodimerization and activation. iCasp9 is based on a modified human caspase 9 fused to a human FK506 binding protein (FKBP) (Straathof et al (2005) Blood 105:4247-4254). It enables conditional dimerization in the presence of a small molecule CID, known as AP1903.

Expression of RQR8 renders T-cells susceptible to anti-CD20 antibody Rituximab but is more compact than the full-length CD20 molecule (Philip, B. et al. (2014) Blood doi: 10.1182/blood-2014-01-545020).

Pharmaceutical Composition

The present invention also relates to a pharmaceutical composition containing a vector or a CAR-expressing T cell of the invention together with a pharmaceutically acceptable carrier, diluent or excipient, and optionally one or more further pharmaceutically active polypeptides and/or compounds. Such a formulation may, for example, be in a form suitable for intravenous infusion.

Method

The present invention also relates to a method for making a cell according to the present invention, which comprises the step of introducing a nucleic acid sequence or vector according to the present invention into a cell.

CAR-expressing cells according to the present invention may either be created ex vivo either from a patient's own peripheral blood (1st party), or in the setting of a haematopoietic stem cell transplant from donor peripheral blood (2nd party), or peripheral blood from an unconnected donor (3rd party). Alternatively, CAR T-cells may be derived from ex-vivo differentiation of inducible progenitor cells or embryonic progenitor cells to T-cells. In these instances, CAR T-cells are generated by introducing DNA or RNA coding for the CAR by one of many means including transduction with a viral vector, transfection with DNA or RNA.

The method may further comprise stimulating the cell with a γδ T cell stimulating agent. As used herein, a ‘γδ T cell stimulating agent’ refers to any agent which selectively stimulates the proliferation and/or survival of γδ T cells from a mixed starting population of cells.

Thus, the resulting cell population is enriched with an increased number of γδ T cells—for example particular γδ T cells expressing a particular γδ TCR receptor—compared with the starting population of cells.

γδ T cell populations produced in accordance with the present invention may be enriched with γδ T cells, for example particular γδ T cells expressing a particular γδ TCR receptor. That is, the γδ T cell population that is produced in accordance with the present invention will have an increased number of γδ T cells. For example, the γδ T cell population of the invention will have an increased number of γδ T cells expressing a particular γδ TCR receptor compared with the γδ T cells in a sample isolated from a subject. That is to say, the composition of the γδ T cell population will differ from that of a “native” T cell population (i.e. a population that has not undergone expansion steps discussed herein), in that the percentage or proportion of γδ T cells will be increased.

The γδ T cell population according to the invention may have at least about 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95 or 100% γδ T cells.

The γδ T cell population according to the invention may have at least about 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95 or 100% γδ T cells expressing a particular γδ TCR receptor.

By way of example, the γδ T cell stimulating agent may be isopentenyl pyrophosphate (IPP); an analog of IPP (e.g. bromohydrin pyrophosphate or (E)-4-Hydroxy-3-methyl-but-2-enyl pyrophosphate); an inhibitor of farnesyl pyrophosphate synthase (FPPS) or an aminobisphosphonate such as zoledronate or pamidronate.

The γδ T cell stimulating agent may be used in combination with a general T cell mitogen, for example a mitogenic cytokine such as IL-2.

Additional methods of stimulating γδ T cells are known in art and include, for example, the use of Concanavalin A (Siegers, G. M. et al. PLoS ONE 6, e16700 (2011)), anti-γδ TCR antibodies immobilized on plastic; engineered artificial antigen presenting cells as feeders and engineered artificial antigen presenting cells coated in anti-γδ TCR antibody (Fisher, J. et al.; Clin. Cancer Res. (2014)).

Method of Treatment

A method for the treatment of disease relates to the therapeutic use of a vector or T cell of the invention. In this respect, the vector or T cell may be administered to a subject having an existing disease or condition in order to lessen, reduce or improve at least one symptom associated with the disease and/or to slow down, reduce or block the progression of the disease.

CAR-expressing T cells may either be created ex vivo either from a patient's own peripheral blood (1st party), or in the setting of a haematopoietic stem cell transplant from donor peripheral blood (2nd party), or peripheral blood from an unconnected donor (3rd party). Alternatively, CAR T-cells may be derived from ex-vivo differentiation of inducible progenitor cells or embryonic progenitor cells to T-cells. In these instances, CAR T-cells are generated by introducing DNA or RNA coding for the CAR by one of many means including transduction with a viral vector, transfection with DNA or RNA.

In one embodiment, the sample comprising γδ T cell may have been previously isolated from the subject.

A CAR T cell according to the present invention may be generated by a method as described herein. In particular, a CAR-expressing T cell for use in a method for the treatment of a disease may be generated by a method comprising the steps of transduction of the T cell with a viral vector or transfection with DNA or RNA encoded the co-stimulatory CAR as described herein and expansion of γδ T cells using a γδ T cell stimulating agent.

The γδ T cell stimulating agent may be isopentenyl pyrophosphate (IPP); an analog of IPP (e.g. bromohydrin pyrophosphate or (E)-4-Hydroxy-3-methyl-but-2-enyl pyrophosphate); an inhibitor of farnesyl pyrophosphate synthase (FPPS) or aminobisphosphonates such as zoledronate or pamidronate, for example.

T cells expressing a CAR molecule of the present invention may be used for the treatment of a various diseases including, for example, cancer, microbial infection and viral infection.

The cancer may be, for example, bladder cancer, breast cancer, colon cancer, endometrial cancer, kidney cancer (renal cell), lung cancer, brain cancer, melanoma, leukaemia, lymphoma, pancreatic cancer, prostate cancer or thyroid cancer.

The methods and uses according to the present invention may be practiced in combination with additional compositions. For example, where the disease to be treated is cancer, the composition of the present invention may be administered in combination with additional cancer therapies such as chemotherapy and/or radiotherapy.

A composition of the present invention may be administered in combination with a γδ T cell stimulating agent such as isopentenyl pyrophosphate (IPP); an analog of IPP (e.g. bromohydrin pyrophosphate or (E)-4-Hydroxy-3-methyl-but-2-enyl pyrophosphate); an inhibitor of farnesyl pyrophosphate synthase (FPPS) or aminobisphosphonates such as zoledronate or pamidronate.

In particular, Zoledronate and Pamidronate can be used for in vivo expansion of Vδ2+γδ T cells in combination with IL-2. There are a number of Phase I clinical trials that have used this approach (see Fisher et al.; Oncolmmunology; 3; e27572).

‘In combination’ may refer to administration of the additional therapy or γδ T cell stimulating agent before, at the same time as or after administration of the composition according to the present invention.

The invention will now be further described by way of Examples, which are meant to serve to assist one of ordinary skill in the art in carrying out the invention and are not intended in any way to limit the scope of the invention.

EXAMPLES Example 1—Generation of γδ T Cells Expressing a Co-Stimulatory CAR

PBMCs were extracted from the blood of healthy donors using Ficoll density gradient separation. They were cultured in RPMI 1640 medium supplemented with 10% FCS, 1% penicillin/streptomycin, 100u/ml human IL-2 and 5 μM zoledronic acid for 5 days.

After 5 days they were transduced with retrovirus containing the CAR construct fused to RQR8, which acts as a marker gene and also provides a Rituximab (αCD20) sensitive suicide gene.

The illustrative CAR described herein includes aGD2-specific scFv, a linker based on the Fc portion of IgG1, a transmembrane domain derived from CD28 and the endodomain of DAP10 (see FIG. 10).

A second illustrative CAR includes a CD33-specific scFv, a linker based on the Fc portion of IgG1, a transmembrane domain derived from CD28 and the endodomain of DAP10 (see FIG. 11).

Co-expression of an anti-GD2-Fc-DAP10 CAR with the endogenous TCR of a γδ T cell was demonstrated (FIG. 4).

Example 2—Killing of GD2+ Cell Lines LAN1 and TC71 by Vδ2 γδT Cells Transduced with the aGD2-Fc-DAP10 CAR

Both the LAN1 and TC71 cells lines are known to express GD2.

Significant killing of GD2+ neuroblastoma cell line LAN1 was only seen when CAR transduced cells were used and not when non-transduced (NT) Vδ2 cells were used as effectors (FIG. 5A).

There was an additive effect against the GD2+ Ewing sarcoma cell line TC71 when the aGD2-Fc-DAP10 CAR was used in combination with 24h zoledronic acid treatment (FIG. 5B).

Addition of the CAR to αβT cells, which lack the signal 1 provided by the γδTCR in response to cellular stress, had no effect on cytotoxicity, unlike the effect of the CAR in Vδ2+γδT cells (FIG. 5C). This indicates that the CAR signal alone is insufficient for T-cell activation.

Expression of the aGD2-Fc-DAP10 CAR in γδ T cells did not result in GD2-specific killing of GD2 negative SK-N-SH cells (FIG. 6).

Example 3—Preservation of CAR Expression Following Prolonged Co-Culture and GD2 Specific Expansion

Co-culture was started 24 days after transduction and serial analyses of cells for the presence of CAR and TCRVδ2 were taken in the presence of irradiated GD2+(LAN1) and GD2− (SK-N-SH) neuroblastoma cells (FIG. 7A).

The expansion of aGD2-Fc-DAP10 transduced Vδ2+ cells was only seen in the presence of irradiated GD2+ target cells (FIG. 7B).

Example 4—Specific Killing of CD33+ AML Cells but not CD33+ Monocytes by γδ T Cells Expressing an Anti-CD33-DAP10 CAR

Equivalent levels of CD33 expression were demonstrated in three AML cell lines and monocytes (FIG. 8).

Vδ2 γδT cells were transduced with either an anti-CD33-Fc-DAP10 or anti-CD33-Fc-CD28-CD3z CAR construct.

The anti-CD33-Fc-CD28-CD3z CAR construct provides signal 1 and signal 2 in the presence of CD33. The anti-CD33-Fc-DAP10 provides signal 2 in the presence of CD33.

Cells transduced with the aCD33-CD28-CD3z CAR killed any CD33 positive cell and did not spare healthy monocytes. Cells transduced with the aCD33-Fc-DAP10 CAR do not kill monocytes (FIG. 9A).

There was significant enhancement of killing of the AML but no enhancement of the killing of monocytes by Vδ2 γδT cells transduced with the aCD33-Fc-DAP10 CAR compared to non-transduced controls (FIG. 9B).

All publications mentioned in the above specification are herein incorporated by reference. Various modifications and variations of the described methods and system of the invention will be apparent to those skilled in the art without departing from the scope and spirit of the invention. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in molecular biology, cellular immunology or related fields are intended to be within the scope of the following claims. 

1. A T cell which expresses a gamma-delta T cell receptor (TCR) and a chimeric antigen receptor (CAR), wherein the CAR comprises; (i) an antigen binding domain; (ii) a transmembrane domain; and (iii) a co-stimulatory intracellular signalling domain; wherein the intracellular signalling domain provides a co-stimulatory signal to the T cell following binding of antigen to the antigen binding domain.
 2. A cell according to claim 1 wherein the antigen binding domain is capable of binding to a tumour-associated antigen (TAA).
 3. A cell according to claim 1 wherein the antigen binding domain is capable of binding to GD2, CD33, CD19 or EGFR.
 4. A cell according to any preceding claim wherein the transmembrane domain comprises a CD8 stalk or a CD28 transmembrane domain.
 5. A cell according to any of claims 1 to 4 wherein the intracellular signalling domain comprises the DAP10, CD28, CD27, 41BB, OX40, CD30, IL2-R, IL7-R, IL21-R, NKp30, NKp44 or DNAM-1 (CD226) signalling domain.
 6. A cell according to any of claims 1 to 4 wherein the intracellular signalling domain comprises the DAP10 signalling domain.
 7. A cell according to any preceding claim wherein the binding of a first antigen to the gamma-delta TCR results in signal 1 production and binding of a second antigen to the antigen binding domain of the CAR results in signal 2 production.
 8. A cell according to any preceding claim wherein the CAR further comprises a spacer domain between the antigen binding domain and the transmembrane domain, for example a CD8 stalk or an Fc region.
 9. A cell according to any preceding claim wherein the gamma-delta TCR is capable of binding to a phosphoantigen; major histocompatibility complex class I chain-related A (MICA); major histocompatibility complex class I chain-related B (MICB); NKG2D ligand 1-6 (ULBP 1-6); CD1c; CD1d; endothelial protein C receptor (EPCR); lipohexapeptide; phycoreythrin or histidyl-tRNA-synthase.
 10. A CAR comprising; (i) an antigen-binding domain; (ii) a transmembrane domain; and (iii) an intracellular signalling domain; wherein the intracellular signalling domain comprises a co-stimulatory intracellular signalling domain but does not comprise a CD3 endodomain.
 11. A CAR according to claim 10 wherein the co-stimulatory intracellular signalling domain is selected from a DAP10, CD28, CD27, 41BB, OX40, CD30, IL2-R, IL7-R, IL21-R, NKp30, NKp44 or DNAM-1 (CD226) signalling domain.
 12. A CAR comprising; (i) an antigen-binding domain; (ii) a transmembrane domain; and (iii) an intracellular signalling domain; wherein the intracellular signalling domain comprises a DAP10 signalling domain.
 13. A CAR according to claim 12 wherein the intracellular signalling domain does not comprise a CD3 endodomain.
 14. A CAR according to any of claims 10 to 13 which is a CAR as defined in any of claims 2 to
 9. 15. A nucleic acid sequence encoding a CAR as defined in any preceding claim.
 16. A vector comprising a nucleic acid sequence as defined in claim
 15. 17. A vector according to claim 16 which is a retroviral vector, a lentiviral vector or a transposon.
 18. A method for making a cell according to any of claims 1 to 9, which comprises the step of introducing: a nucleic acid sequence according to claim 15 or a vector according to claim 16 or 17 into a cell.
 19. A method according to claim 18 wherein the cell is stimulated with a gamma delta T cell stimulating agent.
 20. A method according to claim 19 wherein the gamma-delta T cell stimulating agent is selected from isopentenyl pyrophosphate (IPP); analogs of IPP; and inhibitors of farnesyl pyrophosphate synthase (FPPS).
 21. A method according to claim 19 or 20, wherein the cell is from a sample isolated from a subject.
 22. A pharmaceutical composition comprising a cell according to any of claims 1 to 9, a CAR according to any of claims 10 to 14, a nucleic acid sequence according to claim 15 or a vector according to claim 16 or
 17. 23. A method for treating a disease, which comprises the step of administering a pharmaceutical composition according to claim 22 to a subject.
 24. A method according to claim 23 which comprises the step of administering a gamma-delta T cell stimulating agent to the subject.
 25. A method according to claim 24 wherein the gamma-delta T cell stimulating agent is selected from isopentenyl pyrophosphate (IPP); analogs of IPP; and inhibitors of farnesyl pyrophosphate synthase (FPPS).
 26. A method according to any of claims 23 to 25, which comprises the following steps: (i) isolation of a cell-containing sample from a subject; (ii) transduction or transfection of cells with: a nucleic acid according to claim 15 or a vector according to claim 16 or 17; and (iii) administering the cells from (ii) to the subject.
 27. A pharmaceutical composition according to claim 22 for use in treating and/or preventing a disease.
 28. The use of a cell according to any of claims 1 to 9 in the manufacture of a medicament for treating and/or preventing a disease.
 29. A method according to any of claims 23 to 26 or a use according to claim 24 or 25 wherein the disease is cancer, microbial infection or viral infection.
 30. A method according to any of claims 23 to 26 or a use according to claim 27 or 28 wherein the disease is cancer. 